* [PATCH] mailbox: stm32_ipcc: add spinlock to fix channels concurrent access
@ 2019-05-22 8:25 Arnaud Pouliquen
2019-05-23 6:39 ` Fabien DESSENNE
0 siblings, 1 reply; 2+ messages in thread
From: Arnaud Pouliquen @ 2019-05-22 8:25 UTC (permalink / raw)
To: Jassi Brar, Fabien DESSENNE
Cc: linux-stm32, linux-arm-kernel, linux-kernel, arnaud.pouliquen
Add spinlock protection on IPCC register update to avoid race condition.
Without this fix, stm32_ipcc_set_bits and stm32_ipcc_clr_bits can be
called in parallel for different channels. This results in register
corruptions.
Signed-off-by: Arnaud Pouliquen <arnaud.pouliquen@st.com>
---
drivers/mailbox/stm32-ipcc.c | 37 +++++++++++++++++++++++++++----------
1 file changed, 27 insertions(+), 10 deletions(-)
diff --git a/drivers/mailbox/stm32-ipcc.c b/drivers/mailbox/stm32-ipcc.c
index f91dfb1327c7..5c2d1e1f988b 100644
--- a/drivers/mailbox/stm32-ipcc.c
+++ b/drivers/mailbox/stm32-ipcc.c
@@ -50,6 +50,7 @@ struct stm32_ipcc {
void __iomem *reg_base;
void __iomem *reg_proc;
struct clk *clk;
+ spinlock_t lock; /* protect access to IPCC registers */
int irqs[IPCC_IRQ_NUM];
int wkp;
u32 proc_id;
@@ -58,14 +59,24 @@ struct stm32_ipcc {
u32 xmr;
};
-static inline void stm32_ipcc_set_bits(void __iomem *reg, u32 mask)
+static inline void stm32_ipcc_set_bits(spinlock_t *lock, void __iomem *reg,
+ u32 mask)
{
+ unsigned long flags;
+
+ spin_lock_irqsave(lock, flags);
writel_relaxed(readl_relaxed(reg) | mask, reg);
+ spin_unlock_irqrestore(lock, flags);
}
-static inline void stm32_ipcc_clr_bits(void __iomem *reg, u32 mask)
+static inline void stm32_ipcc_clr_bits(spinlock_t *lock, void __iomem *reg,
+ u32 mask)
{
+ unsigned long flags;
+
+ spin_lock_irqsave(lock, flags);
writel_relaxed(readl_relaxed(reg) & ~mask, reg);
+ spin_unlock_irqrestore(lock, flags);
}
static irqreturn_t stm32_ipcc_rx_irq(int irq, void *data)
@@ -92,7 +103,7 @@ static irqreturn_t stm32_ipcc_rx_irq(int irq, void *data)
mbox_chan_received_data(&ipcc->controller.chans[chan], NULL);
- stm32_ipcc_set_bits(ipcc->reg_proc + IPCC_XSCR,
+ stm32_ipcc_set_bits(&ipcc->lock, ipcc->reg_proc + IPCC_XSCR,
RX_BIT_CHAN(chan));
ret = IRQ_HANDLED;
@@ -121,7 +132,7 @@ static irqreturn_t stm32_ipcc_tx_irq(int irq, void *data)
dev_dbg(dev, "%s: chan:%d tx\n", __func__, chan);
/* mask 'tx channel free' interrupt */
- stm32_ipcc_set_bits(ipcc->reg_proc + IPCC_XMR,
+ stm32_ipcc_set_bits(&ipcc->lock, ipcc->reg_proc + IPCC_XMR,
TX_BIT_CHAN(chan));
mbox_chan_txdone(&ipcc->controller.chans[chan], 0);
@@ -141,10 +152,12 @@ static int stm32_ipcc_send_data(struct mbox_chan *link, void *data)
dev_dbg(ipcc->controller.dev, "%s: chan:%d\n", __func__, chan);
/* set channel n occupied */
- stm32_ipcc_set_bits(ipcc->reg_proc + IPCC_XSCR, TX_BIT_CHAN(chan));
+ stm32_ipcc_set_bits(&ipcc->lock, ipcc->reg_proc + IPCC_XSCR,
+ TX_BIT_CHAN(chan));
/* unmask 'tx channel free' interrupt */
- stm32_ipcc_clr_bits(ipcc->reg_proc + IPCC_XMR, TX_BIT_CHAN(chan));
+ stm32_ipcc_clr_bits(&ipcc->lock, ipcc->reg_proc + IPCC_XMR,
+ TX_BIT_CHAN(chan));
return 0;
}
@@ -163,7 +176,8 @@ static int stm32_ipcc_startup(struct mbox_chan *link)
}
/* unmask 'rx channel occupied' interrupt */
- stm32_ipcc_clr_bits(ipcc->reg_proc + IPCC_XMR, RX_BIT_CHAN(chan));
+ stm32_ipcc_clr_bits(&ipcc->lock, ipcc->reg_proc + IPCC_XMR,
+ RX_BIT_CHAN(chan));
return 0;
}
@@ -175,7 +189,7 @@ static void stm32_ipcc_shutdown(struct mbox_chan *link)
controller);
/* mask rx/tx interrupt */
- stm32_ipcc_set_bits(ipcc->reg_proc + IPCC_XMR,
+ stm32_ipcc_set_bits(&ipcc->lock, ipcc->reg_proc + IPCC_XMR,
RX_BIT_CHAN(chan) | TX_BIT_CHAN(chan));
clk_disable_unprepare(ipcc->clk);
@@ -208,6 +222,8 @@ static int stm32_ipcc_probe(struct platform_device *pdev)
if (!ipcc)
return -ENOMEM;
+ spin_lock_init(&ipcc->lock);
+
/* proc_id */
if (of_property_read_u32(np, "st,proc-id", &ipcc->proc_id)) {
dev_err(dev, "Missing st,proc-id\n");
@@ -259,9 +275,10 @@ static int stm32_ipcc_probe(struct platform_device *pdev)
}
/* mask and enable rx/tx irq */
- stm32_ipcc_set_bits(ipcc->reg_proc + IPCC_XMR,
+ stm32_ipcc_set_bits(&ipcc->lock, ipcc->reg_proc + IPCC_XMR,
RX_BIT_MASK | TX_BIT_MASK);
- stm32_ipcc_set_bits(ipcc->reg_proc + IPCC_XCR, XCR_RXOIE | XCR_TXOIE);
+ stm32_ipcc_set_bits(&ipcc->lock, ipcc->reg_proc + IPCC_XCR,
+ XCR_RXOIE | XCR_TXOIE);
/* wakeup */
if (of_property_read_bool(np, "wakeup-source")) {
--
2.7.4
^ permalink raw reply [flat|nested] 2+ messages in thread* Re: [PATCH] mailbox: stm32_ipcc: add spinlock to fix channels concurrent access
2019-05-22 8:25 [PATCH] mailbox: stm32_ipcc: add spinlock to fix channels concurrent access Arnaud Pouliquen
@ 2019-05-23 6:39 ` Fabien DESSENNE
0 siblings, 0 replies; 2+ messages in thread
From: Fabien DESSENNE @ 2019-05-23 6:39 UTC (permalink / raw)
To: Arnaud POULIQUEN, Jassi Brar; +Cc: linux-stm32, linux-arm-kernel, linux-kernel
Hi Arnaud,
Thank you for the patch.
On 22/05/2019 10:25 AM, Arnaud Pouliquen wrote:
> Add spinlock protection on IPCC register update to avoid race condition.
> Without this fix, stm32_ipcc_set_bits and stm32_ipcc_clr_bits can be
> called in parallel for different channels. This results in register
> corruptions.
>
> Signed-off-by: Arnaud Pouliquen <arnaud.pouliquen@st.com>
Reviewed-by: Fabien Dessenne <fabien.dessenne@st.com>
> ---
> drivers/mailbox/stm32-ipcc.c | 37 +++++++++++++++++++++++++++----------
> 1 file changed, 27 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/mailbox/stm32-ipcc.c b/drivers/mailbox/stm32-ipcc.c
> index f91dfb1327c7..5c2d1e1f988b 100644
> --- a/drivers/mailbox/stm32-ipcc.c
> +++ b/drivers/mailbox/stm32-ipcc.c
> @@ -50,6 +50,7 @@ struct stm32_ipcc {
> void __iomem *reg_base;
> void __iomem *reg_proc;
> struct clk *clk;
> + spinlock_t lock; /* protect access to IPCC registers */
> int irqs[IPCC_IRQ_NUM];
> int wkp;
> u32 proc_id;
> @@ -58,14 +59,24 @@ struct stm32_ipcc {
> u32 xmr;
> };
>
> -static inline void stm32_ipcc_set_bits(void __iomem *reg, u32 mask)
> +static inline void stm32_ipcc_set_bits(spinlock_t *lock, void __iomem *reg,
> + u32 mask)
> {
> + unsigned long flags;
> +
> + spin_lock_irqsave(lock, flags);
> writel_relaxed(readl_relaxed(reg) | mask, reg);
> + spin_unlock_irqrestore(lock, flags);
> }
>
> -static inline void stm32_ipcc_clr_bits(void __iomem *reg, u32 mask)
> +static inline void stm32_ipcc_clr_bits(spinlock_t *lock, void __iomem *reg,
> + u32 mask)
> {
> + unsigned long flags;
> +
> + spin_lock_irqsave(lock, flags);
> writel_relaxed(readl_relaxed(reg) & ~mask, reg);
> + spin_unlock_irqrestore(lock, flags);
> }
>
> static irqreturn_t stm32_ipcc_rx_irq(int irq, void *data)
> @@ -92,7 +103,7 @@ static irqreturn_t stm32_ipcc_rx_irq(int irq, void *data)
>
> mbox_chan_received_data(&ipcc->controller.chans[chan], NULL);
>
> - stm32_ipcc_set_bits(ipcc->reg_proc + IPCC_XSCR,
> + stm32_ipcc_set_bits(&ipcc->lock, ipcc->reg_proc + IPCC_XSCR,
> RX_BIT_CHAN(chan));
>
> ret = IRQ_HANDLED;
> @@ -121,7 +132,7 @@ static irqreturn_t stm32_ipcc_tx_irq(int irq, void *data)
> dev_dbg(dev, "%s: chan:%d tx\n", __func__, chan);
>
> /* mask 'tx channel free' interrupt */
> - stm32_ipcc_set_bits(ipcc->reg_proc + IPCC_XMR,
> + stm32_ipcc_set_bits(&ipcc->lock, ipcc->reg_proc + IPCC_XMR,
> TX_BIT_CHAN(chan));
>
> mbox_chan_txdone(&ipcc->controller.chans[chan], 0);
> @@ -141,10 +152,12 @@ static int stm32_ipcc_send_data(struct mbox_chan *link, void *data)
> dev_dbg(ipcc->controller.dev, "%s: chan:%d\n", __func__, chan);
>
> /* set channel n occupied */
> - stm32_ipcc_set_bits(ipcc->reg_proc + IPCC_XSCR, TX_BIT_CHAN(chan));
> + stm32_ipcc_set_bits(&ipcc->lock, ipcc->reg_proc + IPCC_XSCR,
> + TX_BIT_CHAN(chan));
>
> /* unmask 'tx channel free' interrupt */
> - stm32_ipcc_clr_bits(ipcc->reg_proc + IPCC_XMR, TX_BIT_CHAN(chan));
> + stm32_ipcc_clr_bits(&ipcc->lock, ipcc->reg_proc + IPCC_XMR,
> + TX_BIT_CHAN(chan));
>
> return 0;
> }
> @@ -163,7 +176,8 @@ static int stm32_ipcc_startup(struct mbox_chan *link)
> }
>
> /* unmask 'rx channel occupied' interrupt */
> - stm32_ipcc_clr_bits(ipcc->reg_proc + IPCC_XMR, RX_BIT_CHAN(chan));
> + stm32_ipcc_clr_bits(&ipcc->lock, ipcc->reg_proc + IPCC_XMR,
> + RX_BIT_CHAN(chan));
>
> return 0;
> }
> @@ -175,7 +189,7 @@ static void stm32_ipcc_shutdown(struct mbox_chan *link)
> controller);
>
> /* mask rx/tx interrupt */
> - stm32_ipcc_set_bits(ipcc->reg_proc + IPCC_XMR,
> + stm32_ipcc_set_bits(&ipcc->lock, ipcc->reg_proc + IPCC_XMR,
> RX_BIT_CHAN(chan) | TX_BIT_CHAN(chan));
>
> clk_disable_unprepare(ipcc->clk);
> @@ -208,6 +222,8 @@ static int stm32_ipcc_probe(struct platform_device *pdev)
> if (!ipcc)
> return -ENOMEM;
>
> + spin_lock_init(&ipcc->lock);
> +
> /* proc_id */
> if (of_property_read_u32(np, "st,proc-id", &ipcc->proc_id)) {
> dev_err(dev, "Missing st,proc-id\n");
> @@ -259,9 +275,10 @@ static int stm32_ipcc_probe(struct platform_device *pdev)
> }
>
> /* mask and enable rx/tx irq */
> - stm32_ipcc_set_bits(ipcc->reg_proc + IPCC_XMR,
> + stm32_ipcc_set_bits(&ipcc->lock, ipcc->reg_proc + IPCC_XMR,
> RX_BIT_MASK | TX_BIT_MASK);
> - stm32_ipcc_set_bits(ipcc->reg_proc + IPCC_XCR, XCR_RXOIE | XCR_TXOIE);
> + stm32_ipcc_set_bits(&ipcc->lock, ipcc->reg_proc + IPCC_XCR,
> + XCR_RXOIE | XCR_TXOIE);
>
> /* wakeup */
> if (of_property_read_bool(np, "wakeup-source")) {
^ permalink raw reply [flat|nested] 2+ messages in thread
end of thread, other threads:[~2019-05-23 6:40 UTC | newest]
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2019-05-22 8:25 [PATCH] mailbox: stm32_ipcc: add spinlock to fix channels concurrent access Arnaud Pouliquen
2019-05-23 6:39 ` Fabien DESSENNE
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